JSFiddle - React, Tailwind, and code Playground
HTML
<div id="wrap">
<input type="text" id="inputbox" name="input" placeholder="yes" />
</div>
<div id="counter"></div>
CSS
input {
margin-left:3em;
min-width:100px;
max-width:600px;
}
JavaScript
$(function(){
$('#inputbox').keyup(function(){
$(this).width( $('#inputbox').width() + 5 );
});
});